1. Technical Field
The present invention relates to a technique for absorbing a striking or impact energy exerted on a seat and particularly to a striking energy absorbing seat leg structure capable of absorbing an impact load exerted on a front surface side or an upper surface side of a seat upon accident of a vehicle or an aircraft.
2. Background Art
Various seat shock absorbers have been used heretofore. For example, a striking energy generated in the event of failure in landing of an airplane is mostly absorbed by a shock absorber provided on the airplane body side. In the event of automobile collision, the resulting striking energy is absorbed by a shock absorber provided between a bumper and the chassis.
In a landing failure accident of an airplane or in an automobile collision accident, however, there is sometimes generated an impact load exceeding the impact absorbing ability of a shock absorber, and in this case too large an impact energy is applied to passengers. As the seat particularly in an airplane, in order to absorb such striking energy, there has been used a seat designed so that a special shock absorber is added to a leg portion of the seat or a diagonal member so as to absorb striking energy through a crushing load or a tensile load of the shock absorber.
In the conventional seat as described above, the leg structure such as a leg portion, a diagonal member and so on is firmly fixed by bolts and screws at connecting and fixing portions of front and rear beams, the leg portion and the diagonal member, but this is not a structure such that when the impact is applied to the leg structure, it is deformed by the impact or the striking energy can be absorbed. Accordingly, in such a case as described, the leg structure should be especially provided with parts or devices for absorbing the shock, resulting in a problem such that not only does the leg structure become complicated, but also the weight constituting the seat increases and the leg structure increases in price.
The present invention has been accomplished in view of the aforementioned problems, and it is the object thereof to provide a striking energy absorbing seat leg structure in which a special shock absorber or member is not added to the conventional leg structure but a connecting method of a diagonal member and a leg portion constituting a leg structure is changed to reduce a striking energy applied to the seat through a material characteristic, that is, a plastic deformation of the diagonal member itself, thus enhancing safety of a seat.
It is further an object of the present invention to provide a striking energy absorbing seat leg structure which can minimize an amount of deformation of a seat after shock absorption to enhance safety for passengers.